Samsung Exynos 7870 Advantages
Lower TDP (3W vs 8W)
Samsung Exynos 2100 Advantages
Better graphics card performance FLOPS (1.5304 TFLOPS vs 0.0224 TFLOPS )
Higher Frequency (2900MHz vs 1600MHz)
More modern manufacturing process (5nm vs 14nm)
Released 4 years and 10 months late